Piston and piston-ring



HRRY B. JOHNSTON, OF SEATTLE, WASHNGTON.

PISTON AND PISTOI\ -RNG.

Specification of Letters Patent.

Patented Application led October 27, 191i?. Serial No. 333,?0-4.

To all inizio/n t may concern Be it known that l, Hanni' B. JOHNSTON, a citizen or" the United States, residing at Seattle.. in the county of King and State of Washington, have invented certain new and uset'ul Improvements in Pistons and Tistonspecial and novel construction, whereby7 the gas or steam pressure within the cylinder will act thereon to cause the rings to expand against the cylinder walls, the rings being designed to coact relatively to divide the expansive eifect exerted thereon so that no excessive or binding' action upon the cylinder Walls will result.

The invention consists in the novel construction, adaptation and combination of a piston and the rings therefor7 as will be fully described in the following specification, illustrated in the accompanying drawings, and finally set forth in the appended claims. I

In said drawings, Figure l. is a view in elevation lof a piston and rings therefor constructed in accordance with iny invention, shown partly in section. 2 is a frag-- Incntary sectional view of a piston showing the ring-groove without the rings. Fig. 8 is a fragmentary sectional view oi a piston enibodyingl my invention contained within a cylinder. Fig. Ai: is a view in horizontal section on line 4 4 of Fig. l, the upper ring being broken away. Fig. is a view in elevation, partly in section, ot a pair of rings shown detached.

Referring to said views., the reference numeral l indicates the engine cylinder and 2 a piston operatively mounted therein. Said piston is formed in proximity of its upper end with an annular ring'- groove Whose upper wall 4 is substantially at right angles with the vertical exterior wall of the piston and with the rear wallv 5 of the groove. The bottom wall 6 of the groove is inclined upwardly and inwardly from the exterior Wall of the piston at an angle approximating twenty degrees.

Cooperating in said groove are two paoliing rings and S. Both said rings are formed with vertical and parallel outer and inner faces l0 and ll. respectivefyj while the upper ringI 7 is formed with an upper ice l2 parallel with the upper wall Ll. of the groove The lower ring` 8 is formed clined under face 13 corresponding larityY with the lower 'all if of tl e T he lower iace'l of the upper r n the upper fare 1G o1 the lower ring are in- @lined correspondingrly from tlu1ii7vertical faces and substantiallyY similarly to the-angularity ot' the lower wall Gol" the gro but this similarity oi inclination as between the lower and upper Afaces oil rings 'l' and S on the one hand and the wall i3 on the other, ma;7 be departed from to soineleitent.

The rings are provided with a relatively large cut or opening at l? `and the piston ,groove is formed or provided. with pins iS and 19 arranged upon diarnetiicalljyY opposite sides ot the piston and at elevations., rt spectivcly, so that one of said pins. le, will protrude within the eut y17 of the ring1 S and the other pin 19 will protrude within the cut of the ring` 7 and thus maintain said cuts at opposite sides of the piston so as to insure that said outs will never coincide and thus permit leakage of gas.

The depths of said rings are less than that of the groove so that when 'the rings are in their operative positions within the cylindre. as indicated in Fig; there will remain a. olea ance space Q0 at the rear oi' the groove,

ln operation, when the piston and rin f are mounted in operative condition wit..in a cylinder and the pressure oi gas within the combustion chamber exerts its 'oree upon the piston, a portion of such force w"l be expended upon the piston rings in a ward direction.` .The eilieet ont the prec re will be such thatthc upper ring i" will react upon the uppeniholined face lo of the owen ring and be for/,led outwardly into intr Contact with the cylinder walls on its downs`1 ward stroke and be relieved to seine ent nt on its upward stroke.

The lower ring will also have tend-ener' to follow this saine movement, altlionJv w less extent due to its response to downward pressure having a` reactionary effect ontwar on inclined wall of the groove. lower ring' 8, however, serves espi'eciallv a. ing for the upper ring i' and when the rin become worn from continued use 'the lower with' an in.-

port for the u ring will Serve as a bearing and inclined supxr ring, the wear being compensated for y the movement of the lower ring outward as its vertical face l() is worn away.

Having described my invention, what I claim, isf- 1. A piston having an annular ring groove whose top lWall is at right angles to the vertical side wall of the piston and whose lower opposite wall is inclined upwardly and in`-' wardly from said vertical wall, a piston ring in said groove having its lower and upper faces paralleland inclined correspondin ly to the lower wall of said grooveI` and anoter piston ring superimposed upon said firstnamed ring having its lower face inclined to corres )ond with the upper face of said firstnamed ring.

2. A piston having a working face :uid an annular ring groove whose wall farthest awalv from the working face of the piston is inclined upwardly toward theI working face of the piston and inwardly from the cylindrical surface thereof, a piston ring in said groove, having its lower and upper faces lsubstantially parallel and its face farthest from the working face inclined correspondinglbf/tagthe adjacent wall of the groove, and

I anotnefpiston ring superimposed upon said first named ring having its face farthest from the working face inclined to correspond with the adjacent face of the first named ring and having its face nearest the working face, lying substantiallyin a plane.

3. A piston having a working face and an annular ring groove whose wall farthest away from the working face ofthe piston is inclined upwardly toward the working face in said 

